Hydraulic Sample Questions

1. The metering land of a certain flow control valve behaves like a knife-edged orifice. It flows 6.24 gpm at a pressure drop of 250 psid. What will the flow be if the pressure is increased to 500 psid?

1. 8.82 gpm
2. 12.48 gpm
3. 9.36 gpm
4. 6.24 gpm
5. 24.96 gpm

2. A hydraulic pump, which is operating with an outlet pressure of 1680 psi, is supplying power to three control valves, all of which are in parallel with one another. The first valve draws 8.36 in³/sec, the second draws 12.22 in³/sec and the third draws 3.60 in³/sec. What is the total pump flow for the given condition?

1. 24 in³/sec
2. 1374 in³/sec
3. 22 in³/sec
4. 168 in³/sec
5. 360 in³/sec

3. A motor-driven valve, which requires 10 revolutions to go from full off to full open, is used to fill a tank. Assume the motor runs at 100 rpm, the tank holds 80 liters of liquid and that when open, 50 liter/min flow through the valve. How long does it take for the tank to fill? Assume linearity.

1. 1.65 minutes
2. 2.15 minutes
3. 1.80 minutes
4. 1.50 minutes
5. 1.35 minutes

4. In a turbulent flow the pressure varies

1. quadratically with the flow rate
2. linearly with the flow rate
3. inversely with the flow rate
4. as the square root of the flow rate
5. proportionally to the flow rate

Page Revised: July 14, 2003